Background and Objectives: Recently developed laser lipolysis systems have been disappointing because they require more time to remove the same amount of fat than other liposuction methods. A new Nd:YAG laser has been introduced that uses the 1,444 nm wavelength, better absorbed by fat. Study Design/Materials and Methods: This study consisted of two protocols. The first protocol was an in vivo minipig model. Four 10ร10 cm 2 areas were treated on the back of the first minipig. Using the same total energy and power settings (5,000 J, 8 W), both the 1,064 nm and 1,444 nm lasers were used to irradiate the two cephalic areas. The two caudal areas were irradiated with both lasers, using the maximum power settings (12 W with the 1,064 nm laser, 8 W with the 1,444 nm laser). Another minipig was administered a preoperative injection of tumescent solution and treated with the same condition. Measurements of fat volume with computed tomography and histologic exams were conducted. The second experiment involved in vitro human fat. Equal amounts of human fat, harvested by liposuction, were put into test tubes and irradiated with 1,064 nm and 1,444 nm lasers. Oil production was measured from each test tube. Results: A marked reduction in fat volume and more oil vacuoles and giant cells in histology were identified with the 1,444 nm wavelength compared to the 1,064 nm wavelength. Human fat in the in vitro experiments also revealed more oil production following the use of the 1,444 nm laser. Conclusion: The 1,444 nm Nd:YAG laser showed a greater lipolytic effect compared to the 1,064 nm Nd:YAG laser in in vivo minipig and in vitro human fat experiments. To achieve a full understanding of the effects of 1,444 nm Nd:YAG laser lipolysis on the human body, in vivo experimentation will be necessary.